550 ZOOLOGY SECT. 



connected by a ligamentous band with the scapula. Its mode of 

 formation from a mass of cartilage to the anterior face of which 

 the clavicle, formed as usual in membrane, becomes applied 

 proves that this bone represents a procoracoid as well as a 

 clavicle. In other Insectivora this bone is not developed, and the 

 clavicle is a distinct, long and slender bone, but vestiges of the 

 inner or ventral ends of the coracoid and procoracoid may be 

 recognisable. Sometimes there is a distinct bone intervening 

 between the outer end of the clavicle proper and the acromion 

 process. 



The humerus usually has a supracondylar foramen. In the 

 Moles this is absent, and their humerus is remarkable in other 

 respects, being short, greatly expanded at the extremities, with a 

 prominent deltoid ridge, and with two synovial articular surfaces 

 at the proximal end, one for the glenoid cavity of the scapula, 

 the other for the coraco-clavicle. The radius and ulna are 

 completely developed in all, and are usually distinct, but some- 

 times fused distally. In the carpus the scaphoid and lunar 

 sometimes coalesce, sometimes remain distinct ; an os centrale is 

 usually present. In the Moles the manus is extremely broad, 

 the breadth being increased by the presence of a large, curved, 

 radial sesamoid. 



In the pelvis the symphysis pubis is in some cases elongated, 

 in others short, and sometimes absent, the pubes remaining 

 separated by a wide median ventral cleft. A third trochanter is 

 sometimes represented by a ridge. The fibula usually, though 

 not always, fuses distally with the tibia. 



Skeleton of the Chiroptera (Fig. 1174). The cervical region 

 of the vertebral column is characterised by the absence of any 

 distinct neural spines, and the same holds good to a less extent of 

 the trunk-vertebraB ; the transverse processes of the lumbar region 

 are also rudimentary. The tail varies in development : when it 

 is elongated the component vertebras are long, cylindrical centra 

 without processes. Sagittal and occipital crests are developed in 

 the skull of some species. The facial region is rather elongated, 

 especially in the Megachiroptera (Fig. 1175). Post-orbital pro- 

 cesses of the frontal are present or absent : the zygoma is long and 

 slender : the malar is small and applied to the outer surface of 

 the zygoma. The long and narrow nasals are in some cases 

 united ; the premaxillse are small. The mandible has an angular 

 process in the Microchiroptera, not in the Megachiroptera. The 

 segments of the sternum are sometimes distinct, sometimes united : 

 the presternum has a mesial keel developed in co-ordination with 

 the great size of the pectoral muscles. The sternal ribs are 

 ossified. 



The scapula is large and oval in shape : the spine is near the 

 anterior margin : the post-scapular fossa has ridges for the origin 



